Battle of Antietam

The Battle of Antietam was a major battle of the American Civil War which was fought on 17 September 1862 at Sharpsburg, Maryland.

Following his success at the Second Battle of Bull Run, the Confederate general Robert E. Lee felt confident in his ability to win one last campaign in order to convince the United Kingdom, France, and Russia to side with the Confederacy and pressure the Union into signing an armistice. Lee led his 55,000-strong Army of Northern Virginia into Maryland, sending Stonewall Jackson with around 17,000 of his troops to take Harpers Ferry as his remaining 38,000 troops occupied the railroad junction of Sharpsburg along the Antietam Creek. On 15 September, however, a Union soldier found Lee's battle plans wrapped around a pack of cigars accidentally left behind by the Confederates during their advance; the commander of the Union Army of the Potomac, George B. McClellan, led his army of 87,000 troops to Sharpsburg after 15 hours of idling. He waited until the morning of 17 September to give battle.

At 6:00 AM, Union general Joseph Hooker's corps charged along the Hagerstown Pike to attack Stonewall Jackson's troops hidden in woods beyond Miller's Cornfield; their objective was a plateau near the Dunker Church, edged with artillery. The Union artillery opened fire on Confederates who were launching a counter-charge with bayonets, and the cornfield changed hands 15 times; the 12th Massachusetts lost 224 of its 334 troops. Hooker himself was shot in the foot and carried from the field. As Hooker's men closed in on the Dunker Church, Jackson sent in his reserves under John Bell Hood, whose men were enraged because they missed breakfast, which Hood had promised to be their first real meal in three days. The Confederates counterattacked after their first volley, and the cornfield appeared as if it had been scythed due to the large amounts of cannon fire that the Union soldiers were subjected to. The Union forces withdrew before reinforcements repelled Hood's charging men. When an officer asked Hood where his division was, he replied, "Dead on the field." By 10:00 AM, 10,000 men were dead or wounded, and Jackson's lines held.

The second part of the battle began at the Sunken Road at the center of Lee's line, where two Confederate brigades formed rifle pits and were ordered to hold it at all costs. John B. Gordon assured Lee that his men would hold until the sun went down or victory was won, and he let the Union line get within a few yards before giving the order to fire. Union general Joseph K. Mansfield was killed instantly, and his men were forced to retreat and counterattack five times. Gordon was shot once in the right leg, once in the left arm, and once in the shoulder, but he refused aid in order to observe his troops. A fifth gunshot hit him in the face, leaving him unsconscious, but alive. The Confederates still managed to hold, but a New York regiment found a vantage point from which they could fire down on the defenders, turning the tide of the battle and turning the Sunken Road into "Bloody Lane" with heaps of Confederate bodies three feet deep. The Confederate center splintered, but McClellan decided that it would not be prudent to attack again.

The third part of the battle took place on the Confederate right, where Union general Ambrose Burnside's corps tried to fight its way over a stone bridge over Antietam Creek. Burnside's 12,500 troops faced Robert Toombs' 400 Confederate troops, but the Confederates controlling the bluff over the bridge poured fire onto the Union troops, who had to launch three bloody charges over the course of three hours to break through. The Confederates raced back into the town of Sharpsburg, and Union victory seemed certain. However, A.P. Hill's 3,000-strong Confederate light division, having marched 17 miles to Sharpsburg, arrived in time to counterattack and repulse Burnside's forces. The celebrating Union troops were forced to fall back after Hill attacked, and McClellan refused to send reinforcements. Burnside's retreat ended the battle, and neither side gained any ground. It was the bloodiest day in US history, with 22,717 dead, wounded, or missing (double the casualties of D-Day in 1944).

Lee continued to skirmish with McClellan on 18 September, but he retreated south of the Potomac River with the remaining three-quarters of his original force. McClellan refused to attack and drive the Confederates into the river, as he was again too cautious to make a decisive choice; he had not even committed his reserves to the battle. McClellan had halted Lee's invasion, but he lost an opportunity to win the war in a single day, and President Abraham Lincoln removed McClellan from command for the last time in November 1862, appointing Burnside as the new commander. Lincoln used the boost in morale from the victory to pass the Emancipation Proclamation, which nominally freed all of the slaves outside of the border states and discouraged Britain and France from siding with the Confederates.